The invention relates to a special arrangement of a vertical axis rotary looptaker for readily replenishing the thread supply of a double lockstitch sewing machine, which is a part of an automated sewing device.
Sewing devices for sewing a fabric cut on a workpiece part by means of two parallelly extending stitchlines, which are received in a controlled workpiece clamping plate, commonly are provided with a double-needle sewing machine having two vertical axis rotary looptakers carrying a thread supply. In order to replenish the thread supply, the operator must clear the table, i.e. removing the workpiece respectively transferring a clamped workpiece by means of the feeding unit into a position as not to interfer with the thread supply replenishing procedure. Additionally, the operator must remove the slide plates covering the looptakers.
To indicate a required bobbin change sewing devices of this type are equipped with workpiece counters. Nevertheless, it occurs, that the looptaker thread supply is consumed before the workpiece is finished. In such case, the process of thread supply replenishment becomes even more difficult, since the operator must trigger the built-in thread trimmer to disconnect the needle thread from the partially sewn workpiece prior to removing the workpiece.
As obvious, the thread replenishing procedure is a time consuming process. Furthermore, a special control mechanism is necessary to displace the workpiece clamp as the sewing machine remains inoperative, in order to clear the looptakers. Moreover, the sliding of a partially sewn and even cut workpiece by the workpiece clamp on a workplate presents a problem, since the workpiece parts tend to move relatively to each other.
In the production of setting patch pockets on garments similar automated sewing devices have been applied. Such a sewing device in general is installed with a single-needle double lockstitch machine, which has a horizontal axis rotary looptaker. For this reason, independently of the workpiece clamp position, the looptaker always is easily accessible for thread supply replenishment.